This is an old topic and I have never found an answer. This thread is the latest:
Phonegap: force an app to quit instead of running in background
But it is not a solution either as what I heard was "there is no way and it is not a good experience", etc...
However, if you download OfferUp app. Try to login and logout. The app on iOS will shut itself down. How do they do that? Obviously there is a way and it is approved by App Store. I am wondering if it is still possible with Cordova app?